Adding volume and buttons and updating the Russian translation

[r57zone]

Hi, I've added volume control and buttons, and updated the Russian translation.

On many Android phones, the minimum volume setting doesn’t work well - it jumps by 5%, which can make podcasts, recordings, and audiobooks too loud for listening before bed. This update helps slightly adjust the volume for more comfortable listening in quiet environments.

Thank you for your amazing app and all your hard work!